SEARCH VIA RECURSIVE REJECTION (SERR) - A CONNECTIONIST MODEL OF VISUAL-SEARCH

In studies of visual search, a general distinction is often made between the processes involved when detection of a target is unaffected by the number of distractors in the field and those involved when search time increases linearly as a function of the number of distractors present. In the former case, processes are said to be "pre-attentive" and to operate in parallel across the visual field; in the latter, processing is said to require focal attention and to be spatially serial. In this paper, we present a connectionist model which performs visual search in parallel across a window defining the model’s functional field. Elements in the field are allowed to group, using simple principles of similarity and spatial proximity. Search operates via the recursive rejection of areas of field where stable and unambiguous grouping has been achieved. Performance of the model is unaffected by the number of distractors present when the distractors form a single group. As the number of competing distractor groups increases, there is an increased likelihood that targets are missed. Setting a response criterion to balance miss rates generates serial increases in search time as a function of the number of distractors. These results are shown to match the functions produced when human subjects search displays varying in the number of distractor groups. The implications of the model are discussed, and the results of five experiments are presented that test novel predictions derived from the model. © 1993 Academic Press, Inc.